Method for determining a high-reflection cut of a gem, method for cutting a high-reflection gem, and the cut high-reflection gem

ABSTRACT

The invention relates to a method for determining a high-reflection cut of a gem, a method for cutting a high-reflection gem, and a cut high-reflection gem. According to the invention, the gems have at least three lower part main facets and at least three upper part main facets, the angle between the lower part main facets and the girdle plane being greater than the angle between the upper part main facets and the girdle plane. A table replaces the upper part main facets at an angle of 0°. The lower part main facet angle is between 41° and 46° and the upper part main facet angle corresponds to an angle from a group of predetermined preferred angles. The group of angles is determined according to the average refraction of light n (between 1.50 and 3.00) of the raw material being cut and the lower part main facet angle.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a procedure for determining a high-reflectiongem cut, procedure for cutting a high-reflection gem, and a cut gem ofhigh reflection.

2. Description of the Related Art

The reflection or light efficiency of a gem cut essentially depends onthe dimension and number of facets and on the angles created by them.Many trials have been carried out in the past for improving gem cutsused in practice or for creating new gem cuts. These trials are based,on the one hand, on empirical cutting trials, or [on the other hand] onsimple calculations which also take into account the optical refractionof the raw material to be cut.

For example, DE-AS 1 557 652 specifies combinations of upper part(crown) principal facet angles and lower part (pavilion) principal facetangles for various types of minerals, for example 27°/36° for diamonds,25°/49° for quartz, 24°/45° for tourmaline, 29°/38° for garnet, 28°/39°for beryl, and 28°/39° for corundum.

All these angle combinations have in common the fact that the lower part(pavilion) principal facet angle is larger than the upper part (crown)principal facet angle.

Such cuts, especially for diamonds, with angle combinations of24.5°/39.5°, or of 33.5°/41.5° are also known from DE 42 10 995 A1.

It has been proved in practice that the angle combinations mentioned inthe literature for gem cutting do not yet produce maximum lightefficiency, and that a systematic specification of optimal anglecombinations is very desirable for all materials to be cut, which havedifferent optical refraction.

SUMMARY OF THE INVENTION

Therefore, the objective of the invention is to specify a procedure fordetermining a gem cut, a procedure for gem cutting and a cut gem,whereby optimal light efficiency should be achieved when applying thespecified angle values, while talking into consideration the lightrefraction of the material to be cut.

This objective is solved by a cut gem with characteristics includinghigh reflection with at least three principal pavilion facets and atleast three principal crown facets, the angle between the principalpavilion facets and the girdle surface being greater than the anglebetween the principal crown facets and the girdle surface. At angle 0° atable is formed instead of the principal crown facets, with principalpavilion facet angle (UHFW) ranging between 41° and 46°. Principal crownfacet angle (OHFW) corresponds to an angle selected from a group ofpredetermined, preferred angles, which are subject to mean opticalrefraction n ranging between 1.50 and 3.00 of the raw material to becut, and principal pavilion facet angle (UHFW). The group ofpredetermined, preferred angles includes the following angles:

at n 1.50 and UHFW of 42°angles of 13° to 33°

at n 1.50 and UHFW of 43°angles of 60° to 26°

at n 1.50 and UHFW of 44°angles of 1° to 18°

at n 1.50 and UHFW of 45°angles of 0° to 9°

at n 1.50 and UHFW of 46°angles of 0°

at n 1.55 and UHFW of 41°angles of 18° to 33°

at n 1.55 and UHFW of 42°angles of 12° to 30°

at n 1.55 and UHFW of 43°angles of 6° to 26°

at n 1.55 and UHFW of 44°angles of 1° to 18°

at n 1.55 and UHFW of 45°angles of 0° to 13°

at n 1.55 and UHFW of 46°angles of 0° to 5°

at n 1.60 and UHFW of 41°angles of 17° to 31°

at n 1.60 and UHFW of 42°angles of 11° to 28°

at n 1.60 and UHFW of 43°angles of 6° to 23°

at n 1.60 and UHFW of 44°angles of 1° to 20°

at n 1.60 and UHFW of 45°angles of 0° to 14°

at n 1.60 and UHFW of 46°angles of 0° to 6°

at n 1.65 and UHFW of 41°angles of 16° to 28°

at n 1.65 and UHFW of 42°angles of 11° to 25°

at n 1.65 and UHFW of 43°angles of 5° to 21°

at n 1.65 and UHFW of 44°angles of 1to 17°

at n 1.65 and UHFW of 45°angles of 0° to 14°

at n 1.65 and UHFW of 46°angles of 0° to 6°

at n 1.70 and UHFW of 41°angles of 15° to 27°

at n 1.70 and UHFW of 42°angles of 10° to 23°

at n 1.70 and UHFW of 43°angles of 5° to 20°

at n 1.70 and UHFW of 44°angles of 1° to 17°

at n 1.70 and UHFW of 45°angles of 0° to 12°

at n 1.70 and UHFW of 46°angles of 0° to 6°

at n 1.75 and UHFW of 41°angles of 15° to 25°

at n 1.75 and UHFW of 42°angles of 10° to 22°

at n 1.75 and UHFW of 43°angles of 5° to 19°

at n 1.75 and UHFW of 44°angles of 1° to 15°

at n 1.75 and UHFW of 45°angles of 0° to 12°

at n 1.75 and UHFW of 46°angles of 0° to 3°

at n 1.80 and UHFW of 41°angles of 14° to 24°

at n 1.80 and UHFW of 42°angles of 10° to 21°

at n 1.80 and UHFW of 43°angles of 5° to 19°

at n 1.80 and UHFW of 44°angles of 1° to 14°

at n 1.80 and UHFW of 45°angles of 0°0 to 11°

at n 1.80 and UHFW of 46°angles of 0° to 3°

at n 1.85 and UHFW of 41°angles of 14° to 23°

at n 1.85 and UHFW of 42°angles of 9° to 20°

at n 1.85 and UHFW of 43°angles of 5° to 17°

at n 1.85 and UHFW of 44°angles of 1° to 14°

at n 1.85 and UHFW of 45°angles of 0° to 11°

at n 1.85 and UHFW of 46°angles of 0° to 3°

at n 1.90 and UHFW of 41°angles of 14° to 22°

at n 1.90 and UHFW of 42°angles of 9° to 20°

at n 1.90 and UHFW of 43°angles of 5° to 17°

at n 1.90 and UHFW of 44°angles of 1° to 14°

at n 1.90 and UHFW of 45°angles of 0° to 9°

at n 1.90 and UHFW of 46°angles of 0° to 3°

at n 1.95 and UHFW of 46°angles of 13° to 22°

at n 1.95 and UHFW of 42°angles of 9° to 20°

at n 1.95 and UHFW of 43°angles of 5° to 16°

at n 1.95 and UHFW of 44°angles of 1° to 13°

at n 1.95 and UHFW of 45°angles of 0° to 9°

at n 1.95 and UHFW of 46°angles of 0° to 3°

at n 2.00 and UHFW of 41°angles of 13° to 22°

at n 2.00 and UHFW of 42°angles of 8° to 17°

at n 2.00 and UHFW of 43°angles of 4° to 16°

at n 2.00 and UHFW of 44°angles of 1° to 12°

at n 2.00 and UHFW of 45°angles of 0° to 9°

at n 2.00 and UHFW of 46°angles of 0° to 3°

at n 2.05 and UHFW of 41°angles of 13° to 19°

at n 2.05 and UHFW of 42°angles of 8° to 16°

at n 2.05 and UHFW of 43°angles of 4° to 14°

at n 2.05 and UHFW of 44°angles of 1° to 12°

at n 2.05 and UHFW of 45°angles of 0° to 9°

at n 2.05 and UHFW of 46°angles of 0° to 3°

at n 2.10 and UHFW of 41°angles of 12° to 19°

at n 2.10 and UHFW of 42°angles of 8° to 16°

at n 2.10 and UHFW of 43°angles of 4° to 14°

at n 2.10 and UHFW of 44°angles of 1° to 12°

at n 2.10 and UHFW of 45°angles of 0° to 8°

at n 2.10 and UHFW of 46°angles of 0° to 3°

at n 2.15 and UHFW of 41°angles of 12° to 18°

at n 2.15 and UHFW of 42°angles of 8° to 16°

at n 2.15 and UHFW of 43°angles of 4° to 14°

at n 2.15 and UHFW of 44°angles of 1° to 11°

at n 2.15 and UHEW of 45°angles of 0° to 8°

at n 2.15 and UHEW of 46°angles of 0° to 4°

at n 2.15 and UHFW of 41°angles of 12° to 17°

at n 2.20 and UHFW of 42°angles of 8° to 15°

at n 2.20 and UHFW of 43°angles of 4° to 13°

at n 2.20 and UHFW of 44°angles of 1° to 10°

at n 2.20 and UHFW of 45°angles of 0° to 8°

at n 2.20 and UHFW of 46°angles of 0° to 4°

at n 2.20 and UHFW of 41°angles of 12° to 17°

at n 2.25 and UHFW of 42°angles of 8° to 15°

at n 2.25 and UHFW of 43°angles of 4° to 13°

at n 2.25 and UHFW of 44°angles of 1° to 10°

at n 2.25 and UHFW of 45°angles of 0° to 8°

at n 2.25 and UHFW of 46°angles of 0° to 3°

at n 2.30 and UHFW of 41°angles of 12° to 17°

at n 2.30 and UHFW of 42°angles of 7° to 15°

at n 2.30 and UHFW of 43°angles of 4° to 13°

at n 2.30 and UHFW of 44°angles of 1° to 10°

at n 2.30 and UHFW of 45°angles of 0° to 7°

at n 2.30 and UHFW of 46°angles of 0° to 3°

at n 2.35 and UHFW of 41°angles of 11° to 17°

at n 2.35 and UHFW of 42°angles of 7° to 14°

at n 2.35 and UHFW of 43°angles of 4° to 12°

at n 2.35 and UHFW of 44°angles of 1° to 10°

at n 2.35 and UHFW of 45°angles of 0° to 7°

at n 2.35 and UHFW of 46°angles of 0° to 3°

at n 2.40 and UHFW of 41°angles of 11° to 16°

at n 2.40 and UHFW of 42°angles of 7° to 14°

at n 2.40 and UHFW of 43°angles of 4° to 12°

at n 2.40 and UHFW of 44°angles of 1° to 10°

at n 2.40 and UHFW of 45°angles of 0° to 7°

at n 2.40 and UHFW of 46°angles of 0° to 3°

at n 2.45 and UHFW of 41°angles of 11° to 16°

at n 2.45 and UHEW of 42°angles of 7° to 14°

at n 2.45 and UHFW of 43°angles of 4° to 12°

at n 2.45 and UHFW of 44°angles of 1° to 1°

at n 2.45 and UHFW of 45°angles of 0° to 7°

at n 2.45 and UHFW of 46°angles of 0° to 3°

at n 2.50 and UHFW of 41°angles of 11° to 16°

at n 2.50 and UHFW of 42°angles of 7° to 14°

at n 2.50 and UHFW of 43°angles of 4° to 11°

at n 2.50 and UHFW of 44°angles of 1° to 9°

at n 2.50 and UHFW of 45°angles of 0° to 7°

at n 2.50 and UHFW of 46°angles of 0° to 3°

at n 2.55 and UHFW of 41°angles of 11° to 15°

at n 2.55 and UHFW of 42°angles of 7° to 13°

at n 2.55 and UHFW of 43°angles of 4° to 11°

at n 2.55 and UHFW of 44°angles of 1° to 9°

at n 2.55 and UHFW of 45°angles of 0° to 7°

at n 2.55 and UHFW of 46°angles of 0° to 2°

at n 2.60 and UHFW of 41°angles of 11° to 15°

at n 2.60 and UHFW of 42°angles of 7° to 13°

at n 2.60 and UHFW of 43°angles of 4° to 11°

at n 2.60 and UHFW of 44°angles of 1° to 9°

at n 2.60 and UHFW of 45°angles of 0° to 7°

at n 2.60 and UHFW of 46°angles of 0° to 2°

at n 2.65 and UHFW of 41°angles of 10° to 15°

at n 2.65 and UHFW of 42°angles of 7° to 13°

at n 2.65 and UHFW of 43°angles of 4° to 11°

at n 2.65 and UHFW of 44°angles of 1° to 9°

at n 2.65 and UHFW of 45°angles of 0° to 6°

at n 2.65 and UHFW of 46°angles of 0° to 2°

at n 2.70 and UHFW of 41°angles of 10° to 15°

at n 2.70 and UHFW of 42°angles of 7° to 13°

at n 2.70 and UHFW of 43°angles of 4° to 11°

at n 2.70 and UHFW of 44°angles of 1° to 9°

at n 2.70 and UHFW of 45°angles of 0° to 6°

at n 2.70 and UHFW of 46°angles of 0° to 2°

at n 2.75 and UHFW of 41°angles of 10° to 15°

at n 2.75 and UHFW of 42°angles of 7° to 12°

at n 2.75 and UHFW of 43°angles of 4° to 11°

at n 2.75 and UHFW of 44°angles of 1° to 9°

at n 2.75 and UHFW of 45°angles of 0° to 6°

at n 2.75 and UHFW of 46°angles of 0° to 1°

at n 2.80 and UHFW of 41°angles of 10° to 15°

at n 2.80 and UHFW of 42°angles of 7° to 12°

at n 2.80 and UHFW of 43°angles of 4° to 10°

at n 2.80 and UHFW of 44°angles of 1° to 8°

at n 2.80 and UHFW of 45°angles of 0° to 6°

at n 2.80 and UHFW of 46°angles of 0° to 1°

at n 2.85 and UHFW of 41°angles of 10° to 14°

at n 2.85 and UHFW of 42°angles of 7° to 12°

at n 2.85 and UHFW of 43°angles of 4° to 10°

at n 2.85 and UHFW of 44°angles of 1° to 8°

at n 2.85 and UHFW of 45°angles of 0° to 6°

at n 2.85 and UHFW of 46°angles of 0° to 1°

at n 2.90 and UHFW of 41°angles of 10° to 14°

at n 2.90 and UHFW of 42°angles of 7° to 12°

at n 2.90 and UHFW of 43°angles of 4° to 10°

at n 2.90 and UHFW of 44°angles of 1° to 8°

at n 2.90 and UHFW of 45°angles of 0° to 6°

at n 2.90 and UHFW of 46°angles of 0° to 1°

at n 2.95 and UHFW of 41°angles of 10° to 14°

at n 2.95 and UHFW of 42°angles of 7° to 12°

at n 2.95 and UHFW of 43°angles of 4° to 10°

at n 2.95 and UHFW of 44°angles of 10° to 8°

at n 2.95 and UHFW of 45°angles of 0° to 6°

at n 2.95 and UHFW of 46°angles of 0° to 1°

at n 3.00 and UHFW of 41°angles of 10° to 14°

at n 3.00 and UHFW of 42°angles of 7° to 12°

at n 3.00 and UHFW of 43°angles of 4° to 10°

at n 3.00 and UHFW of 44°angles of 1° to 8°

at n 3.00 and UHFW of 45°angles of 0° to 6°

at n 3.00 and UHFW of 46°angles of 0° to 1°

Principal crown facet angles (OHFW) for values of n and principalpavilion facet angles (UHFW) not specifically specified above may beinterpolated from the above specified values. Within the group of anglesjust specified, a group of especially preferred angles includes:

at n 1.50 and UHFW of 42°angles of 16° to to 25°

at n 1.50 and UHFW of 43°angles of 10° to 21°

at n 1.50 and UHFW of 44°angles of 3° to 16°

at n 1.50 and UHFW of 45°angles of 0° to 9°

at n 1.55 and UHFW of 41°angles of 20° to 26°

at n 1.55 and UHFW of 42°angles of 15° to 23°

at n 1.55 and UHFW of 43°angles of 9° to 19°

at n 1.55 and UHFW of 44°angles of 3° to 16°

at n 1.55 and UHFW of 45°angles of 0° to 8°

at n 1.60 and UHFW of 41°angles of 19° to 25°

at n 1.60 and UHFW of 42°angles of 14° to 21°

at n 1.60 and UHFW of 43°angles of 8° to 17°

at n 1.60 and UHFW of 44°angles of 2° to 12°

at n 1.60 and UHFW of 45°angles of 0° to 7°

at n 1.60 and UHFW of 46°angles of 0°

at n 1.65 and UHFW of 41°angles of 19° to 23°

at n 1.65 and UHFW of 42°angles of 13° to 20°

at n 1.65 and UHFW of 43°angles of 8° to 15°

at n 1.65 and UHFW of 44°angles of 2° to 11°

at n 1.65 and UHFW of 45°angles of 0° to 6°

at n 1.65 and UHFW of 46°angles of 0°

at n 1.70 and UHFW of 41°angles of 18° ° 0 to 21°

at n 1.70 and UHFW of 42°angles of 120 to 18°

at n 1.70 and UHFW of 43°angles of 70 to 14°

at n 1.70 and UHFW of 44°angles of 2° to 11°

at n 1.70 and UHFW of 45°angles of 0° to 6°

at n 1.70 and UHFW of 46°angles of 0°

at n 1.75 and UHFW of 41°angles of 170 to 21°

at n 1.75 and UHFW of 42°angles of 120 to 16°

at n 1.75 and UHFW of 43°angles of 70 to 13°

at n 1.75 and UHFW of 44°angles of 20 to 11°

at n 1.75 and UHFW of 45°angles of 0° to 6°

at n 1.75 and UHFW of 46°angles of 0° to 1°

at n 1.80 and UHFW of 41°angles of 160 to 19°

at n 1.80 and UHFW of 42°angles of 120 to 16°

at n 1.80 and UHFW of 43°angles of 70 to 13°

at n 1.80 and UHFW of 44°angles of 20 to 10°

at n 1.80 and UHFW of 45°angles of 0° to 6°

at n 1.80 and UHFW of 46°angles of 0° to 1°

at n 1.85 and UHFW of 41°angles of 16° to 18°

at n 1.85 and UHFW of 42°angles of 110 to 15°

at n 1.85 and UHFW of 43°angles of 60 to 12°

at n 1.85 and UHFW of 44°angles of 20 to 10°

at n 1.85 and UHFW of 45°angles of 0° to 6°

at n 1.85 and UHFW of 46°angles of 0°

at n 1.90 and UHFW of 41°angles of 160 to 18°

at n 1.90 and UHFW of 42°angles of 110 to 14°

at n 1.90 and UHFW of 43°angles of 60 to 12°

at n 1.90 and UHFW of 44°angles of 20 to 9°

at n 1.90 and UHFW of 45°angles of 0° to 6°

at n 1.90 and UHFW of 46°angles of 0°

at n 1.95 and UHFW of 41°angles of 15° to 17°

at n 1.95 and UHFW of 42°angles of 11° to 14°

at n 1.95 and UHFW of 43°angles of 6° to 12°

at n 1.95 and UHFW of 44°angles of 2° to 9°

at n 1.95 and UHFW of 45°angles of 0° to 6°

at n 1.95 and UHFW of 46°angles of 0°

at n 2.00 and UHFW of 41°angles of 15° to 17°

at n 2.00 and UHFW of 42°angles of 10° to 14°

at n 2.00 and UHFW of 43°angles of 6° to 12°

at n 2.00 and UHFW of 44°angles of 2° to 9°

at n 2.00 and UHFW of 45°angles of 0° to 6°

at n 2.00 and UHFW of 46°angles of 0°

at n 2.05 and UHFW of 41°angles of 15° to 17°

at n 2.05 and UHFW of 42°angles of 10° to 14°

at n 2.05 and UHFW of 43°angles of 6° to 11°

at n 2.05 and UHFW of 44°angles of 2° to 9°

at n 2.05 and UHFW of 45°angles of 0° to 6°

at n 2.05 and UHFW of 46°angles of 0°

at n 2.10 and UHFW of 41°angles of 14° to 16°

at n 2.10 and UHFW of 41°angles of 10° to 14°

at n 2.10 and UHFW of 43°angles of 6° to 11°

at n 2.10 and UHFW of 44°angles of 2° to 9°

at n 2.10 and UHFW of 45°angles of 0° to 6°

at n 2.10 and UHFW of 46°angles of 0°

at n 2.15 and UHFW of 41°angles of 14° to 16°

at n 2.15 and UHFW of 42°angles of 10° to 13°

at n 2.15 and UHFW of 43°angles of 5° to 11°

at n 2.15 and UHFW of 44°angles of 2° to 9°

at n 2.15 and UHFW of 45°angles of 0° to 6°

at n 2.15 and UHFW of 46°angles of 0°

at n 2.20 and UHFW of 46°angles of 14° to 15°

at n 2.20 and UHFW of 42°angles of 10° to 13°

at n 2.20 and UHFW of 43°angles of 5° to 11°

at n 2.20 and UHFW of 44°angles of 2° to 8°

at n 2.20 and UHFW of 45°angles of 0° to 5°

at n 2.20 and UHFW of 46°angles of 0°

at n 2.25 and UHFW of 41°angles of 14° to 15°

at n 2.25 and UHFW of 42°angles of 10° to 13°

at n 2.25 and UHFW of 43°angles of 5° to 11°

at n 2.25 and UHFW of 44°angles of 2° to 8°

at n 2.25 and UHFW of 45°angles of 0° to 5°

at n 2.25 and UHFW of 46°angles of 0°

at n 2.30 and UHFW of 41°angles of 14° to 15°

at n 2.30 and UHFW of 42°angles of 9° to 13°

at n 2.30 and UHFW of 43°angles of 5° to 10°

at n 2.30 and UHFW of 44°angles of 2° to 8°

at n 2.30 and UHFW of 45°angles of 0° to 5°

at n 2.30 and UHFW of 46°angles of 0°

at n 2.35 and UHFW of 41°angles of 13° to 15°

at n 2.35 and UHFW of 42°angles of 9° to 12°

at n 2.35 and UHFW of 43°angles of 5° to 10°

at n 2.35 and UHFW of 44°angles of 2° to 7°

at n 2.35 and UHFW of 45°angles of 0° to 5°

at n 2.35 and UHFW of 46°angles of 0°

at n 2.40 and UHFW of 41°angles of 13° to 14°

at n 2.40 and UHFW of 42°angles of 9° to 12°

at n 2.40 and UHFW of 43°angles of 5° to 9°

at n 2.40 and UHFW of 44°angles of 2° to 7°

at n 2.40 and UHFW of 45°angles of 0° to 4°

at n 2.40 and UHFW of 46°angles of 0°

at n 2.45 and UHFW of 41°angles of 13° to 14°

at n 2.45 and UHFW of 42°angles of 9° to 11°

at n 2.45 and UHFW of 43°angles of 5° to 9°

at n 2.45 and UHFW of 44°angles of 2° to 7°

at n 2.45 and UHFW of 45°angles of 0° to 4°

at n 2.45 and UHFW of 46°angles of 0°

at n 2.50 and UHFW of 41°angles of 13°

at n 2.50 and UHFW of 42°angles of 9° to 11°

at n 2.50 and UHFW of 43°angles of 5° to 9°

at n 2.50 and UHFW of 44°angles of 2° to 7°

at n 2.50 and UHFW of 45°angles of 0° to 4°

at n 2.55 and UHFW of 41°angles of 13°

at n 2.55 and UHFW of 42°angles of 9° to 11°

at n 2.55 and UHFW of 43°angles of 5° to 9°

at n 2.55 and UHFW of 44°angles of 2° to 7°

at n 2.55 and UHFW of 45°angles of 0° to 3°

at n 2.60 and UHFW of 41°angles of 13°

at n 2.60 and UHFW of 42°angles of 9° to 11°

at n 2.60 and UHFW of 43°angles of 5° to 9°

at n 2.60 and UHFW of 44°angles of 2° to 7°

at n 2.60 and UHFW of 45°angles of 0° to 3°

at n 2.65 and UHFW of 42°angles of 9° to 11°

at n 2.65 and UHFW of 43°angles of 5° to 9°

at n 2.65 and UHFW of 44°angles of 2° to 6°

at n 2.65 and UHFW of 45°angles of 0° to 3°

at n 2.70 and UHFW of 42°angles of 9° to 10°

at n 2.70 and UHFW of 43°angles of 5° to 9°

at n 2.70 and UHFW of 44°angles of 2° to 6°

at n 2.70 and UHFW of 45°angles of 0° to 3°

at n 2.75 and UHFW of 42°angles of 9° to 10°

at n 2.75 and UHFW of 43°angles of 5° to 8°

at n 2.75 and UHFW of 44°angles of 2° to 6°

at n 2.75 and UHFW of 45°angles of 0° to 3°

at n 2.80 and UHFW of 42°angles of 9° to 10°

at n 2.80 and UHFW of 43°angles of 5° to 8°

at n 2.80 and UHFW of 44°angles of 2° to 6°

at n 2.80 and UHFW of 45°angles of 0° to 3°

at n 2.85 and UHFW of 42°angles of 9°

at n 2.85 and UHFW of 43°angles of 5° to 8°

at n 2.85 and UHFW of 44°angles of 2° to 6°

at n 2.85 and UHFW of 45°angles of 0° to 3°

at n 2.90 and UHFW of 42°angles of 9°

at n 2.90 and UHFW of 43°angles of 5° to 8°

at n 2.90 and UHFW of 44°angles of 2° to 6°

at n 2.90 and UHFW of 45°angles of 0° to 3°

at n 2.95 and UHFW of 42°angles of 8° to 9°

at n 2.95 and UHFW of 43°angles of 5° to 8°

at n 2.95 and UHFW of 44°angles of 2° to 6°

at n 2.95 and UHFW of 45°angles of 0° to 3°

at n 3.00 and UHFW of 42°angles of 8° to 9°

at n 3.00 and UHFW of 43°angles of 5° to 8°

at n 3.00 and UHFW of 44°angles of 2° to 6°

at n 3.00 and UHFW of 45°angles of 0° to 3°

Principal crown facet angles (OHFW) for values of n and principalpavilion facet angles (UHFW) not specifically specified above may beinterpolated from the above specified values.

According to additional embodiments the cut gem may further include anumber of principal crown facets, the stone having a table of a diameterwhich preferably amounts to 0 to 85% of the diameter of the girdlesurface.

For a diamond, the group of preferred principal crown facet angles(OHFW) according to an embodiment of the present invention comprises thefollowing angles:

with UHFW of 41°angles of 11° to

with UHFW of 42°angles of 7° to 14°

with UHFW of 43°angles of 4° to 12°

with UHFW of 44°angles of 1° to 10°

with UHFW of 45°angles of 0° to 7°

with UHFW of 46°angles of 0° to 3°

According to another embodiment of the invention, within the group ofpreferred angles from which the principal crown facet angle is selectedis a group of especially preferred principal crown facet angles (OHFW)which comprises the following angles:

with UHFW of 41°angles of 13° to 14°

with UHFW of 42°angles of 9° to 12°

with UHFW of 43°angles of 5° to 9°

with UHFW of 44°angles of 2° to 7°

with UHFW of 45°angles of 0° to 4°

with UHFW of 46°angles of 0°

The raw material used for cutting the cut gem may be either a naturalstone or synthetic material.

In addition to principal pavilion facets (UHFW) and principal crownfacets (OHFW), the gem stone may include additional dependent pavilionfacets and/or dependent crown facets. According to such embodiment, theprincipal crown facets may have an angle selected from the group ofespecially preferred principal crown facet angles (OHFW) and thedependent crown facets may have an angle selected from the group ofpreferred angles.

The number of pavilion facets and/or and the number of crown facets maybe an even or an odd number. According to one preferred embodiment, thenumber of pavilion facets and/or the number of crown facets is greaterthan 13.

Furthermore the edges between the principal pavilion facets and theprincipal crown facets may be mutually offset on the girdle surface. Thegirdle surface may be of any shape, and may be either formed as an edgebetween the pavilion facets and the crown facets, or consist of one orseveral rounded or flat facets of any height. The gem stone according tothe invention may be either manually or automatically cut.

By systematic cutting trials and by systematically calculating thereflection (light efficiency) as a function of the preselected cutangle, while simulating various lighting conditions, it has beenestablished that optimal reflection may only be realized within a narrowrange of 41° to 46° of the lower part (pavilion) principal facet angle.As a function of a lower part (pavilion) principal facet angle, and of amean optical refraction of the raw material to be cut between n 1.50 and3.00, a relatively limited number of angles resulting in a high degreeof reflection for the cut gems is produced for the upper part (crown)principal facets. This angle range is described as the preferred anglerange. The greatest light efficiency results from a generally smallerrange of especially preferred angles.

A high-reflection gem cut can therefore be determined for an availablenatural or synthetic uncut gem, so as to result in optimal utilizationof the existing raw material. Determining the cut may be done withoutfurther technical auxiliary materials, simply by following the specifiedtechnical theory. However, it is also possible to determine for theavailable uncut gem a computer-controlled cut of optimal lightefficiency. Thus, the dimensions of an uncut gem, for example, can beoptically measured by an already known computer-controlled system.Adjusting a cut to the required dimensions is also part of the state ofthe art. If, on the basis of the invention, the preferred or especiallypreferred angle combination and the light refraction of the material tobe processed are entered into the computer program of the automaticmachine, it becomes automatically possible to achieve a high reflectioncut and optimal material utilization (weight).

Cutting the gem with the values determined in this way may beimplemented manually or automatically, and even without further manualhandling of the stone after it was optically measured. According to thepresent state of the art, such automatic measuring and cutting machinesare commercially available.

With natural raw material, a finished gem with facets may naturally onlybe obtained by a cutting procedure. For synthetic material, such asglass, additional alternatives are available, such as molding, pressingforming, etc., which are considered equivalent to the cutting aprocedure applicable to natural material.

If, in the aforementioned system, high light efficiency occurs when agroup of upper part (crown) principal facet angles enclose an angle of0°, then instead of a minimum of three principal crown facets at anangle of 0°, one table is produced. Thus, practically speaking, at anangle of 0° several principal crown facets merge into one table. If theprincipal crown facet angle differs from 0°, then an additional tablemay be present. Supplementary to the principal crown facets and theprincipal pavilion facets, additional dependent facets may exist,resulting in especially high light efficiency when the principal crownfacets are within the range of especially preferred angles, and thedependent crown facets are within the range of preferred angles.

Gems can be cut with an even and/or odd number of principal crown facetsor principal pavilion facets, whereby the number of principal crownfacets is equal to, or differs from the number of principal pavilionfacets. An especially high light efficiency results from any even or oddnumber of facets which is greater than 13.

The edges of the principal crown facets and those of the principalpavilion facets may abut on the girdle surface; the surfaces, however,may also be mutually offset.

The girdle surface may have any shape and may, for example, be round,oval, square, or rectangular. The girdle may be made in the form of anedge located between the facets of the pavilion and the facets of thecrown; however, it also may consist of one or more rounded or flatsurfaces of any chosen height.

In case of cuts with several crown facets and/or a few pavilion facets,usually the principal facets are larger than the various dependentfacets. Additional examples and definitions can be derived from theembodiment examples.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained below by means of the drawings showing:

FIGS. 1 to 6 graphic presentation of preferred and especially preferredprincipal crown facet angles as a function of optical refraction forvarious principal pavilion facet angles ranging from 41° to 46°;

FIGS. 7 to 9 graphic presentation of preferred and especially preferredprincipal crown facet angles as a function of principal pavilion facetangles for various optical refraction values ranging from 1.50 to 3.00;

FIGS. 10 to 13 schematic cross sections through cut gems viewed parallelto the girdle surface.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1 to 9 show groups of preferred (light gray) and especiallypreferred (dark gray) principal crown facet angles (OHFW) dependent onoptical refraction n of the material to be cut and on principal pavilionfacet angle (UHFW); these specific values can also be taken fromTable 1. For not explicitly specified values n and unspecified principalpavilion facet angles, i.e. for interim values between integers 41° to46°, an expert can easily interpolate preferred and especially preferredprincipal crown facet angles.

FIG. 10 schematically presents cuts in which girdles 6 are made of around ring-shaped surface positioned between principal pavilion facets 3and principal crown facets 4.

Principal pavilion facet angles 1 range from 41° to 46° and, dependingon optical refraction n, principal crown facet angles 2 correspond to anangle from the group of preferred angles. Left column (a) includes cutswithout table; for cuts shown in the middle of the page (b), thediameter of table 5 is about 50% of the diameter of girdle 6. A gem witha principal crown facet angle of 0° (c) is shown on the right side ofthe page. In this case, principal crown facets 4 coincide with table 5and the girdle surface.

FIG. 11 shows various shapes of the girdle. It may consist of a roundedsurface (a) or of a number of flat facets 7 (b, d, e).Thereby, girdlefacets 7 may have different heights H, they may be arranged at an angleof 90° to the girdle surface (b, d), or they may form with it an anglediffering from 90° (e). FIG. 11 (c) shows a cut in which principal crownfacets 4 and principal pavilion facets 3 create a joint edge. Thus,girdle 6 may consist of a single line.

FIG. 12 shows various divisions of principal crown facets 4 andprincipal pavilion facets 3. Thereby, when equally divided, the facetedges may adjoin each other (a) on the girdle or may be mutually offset(b). The number of principal crown facets 4 may be smaller than thenumber of principal pavilion facets 3 (c) or vice versa (d).

FIG. 13 shows cuts having, in addition to principal facets 3, 4 alsodependent crown facets 8 and dependent pavilion facets 9.

In case of several facet types, the principal pavilion facets selectedin this example should be considered to be the larger facets extendingfrom the tip to the girdle (FIG. 13a), or those constitute the lowestfacet row and converging at the tip (FIG. 13b).

In case of several facet types, the principal crown facets selected inthis example should be considered to be the larger facets, extendingfrom the girdle to the table (FIG. 1a), or the larger facets whichconstitute the center facet row in case of three facet rows (FIG. 13b,c).

FIG. 13(a) shows a brilliant cut, FIG. 13(b) a stepped cut. In FIG.13(c) principal crown facets 4, 8 are laid out in a ring shape, in theform of conical reflection trajectories.

TABLE 1 Summary of preferred and especially preferred principal crownfacet angles (OHFW) as a function of light refraction n and of theprincipal pavilion facet angles (UHFW) preferred principal crown facetangles (OHFW) especially preferred principal crown facet UHFW angles(OHFW) n 1,50 41° 42° 13,14,15, 16,17,18,19,20,21, 26,27,28,29,30,31,22,23,24,25, 32,33, 43° 6,7,8,9, 10,11,12,13,14,15, 22,23,24,25,2616,17,18,19,20,21, 44° 1,2, 3,4,5,6,7,8,9,10,11, 17,18, 12,13,14,15,16,45° 0,1,2,3,4,5,6,7,8,9, 46° 0 n 1,55 41° 18,19, 20,21,22,23,24,25,27,28,29,30,31,32, 26, 33, 42° 12,13,14, 15,16,17,18,19,20,24,25,26,27,28,29, 21,22,23, 30, 43° 6,7,8, 9,10,11,12,13,14,20,21,22,23,24,25, 15,16,17,18,19, 26, 44° 1,2, 3,4,5,6,7,8,9,10, 17,18,11,12,13,14,15,16, 45° 0,1,2,3,4,5,6,7,8, 9,10,11,12,13, 46° 0,1,2,3,4,5, n 1,60 41° 17,18, 19,20,21,22,23,24, 26,27,26,29,30,31, 25, 42°11,12,13, 14,15,16,17,18,19, 22,23,24,25,26,27, 20,21, 28, 43° 6,7,8,9,10,11,13,14,15, 18,19,20,21,22,23, 16,17, 44° 1 2,3,4,5,6,7,8,9,10,13,14,15,16,17,18, 11,12, 19,20, 45° 0,1,2,3,4,5,6, 8,9,10,11,12,13,14,46° 0 1,2,3,4,5,6, n 1,65 41° 16,17,18, 19,20,21,22,23, 24,25,26,27,28,42° 11,12, 13,14,15,16,17, 21,22,23,24,25, 18,19,20, 43° 5,6,7,8,9,10,11,12,13,14, 16,17,18,19,20,21, 15, 44° 2,3,4,5,6,7,8,9,10,11,13,14,15,16,17, 11, 45° 1 0,1,2,3,4,5,6, 7,8,9,10,11,12,13, 14, 46° 01,2,3,4,5,6, n 1,70 41° 15,16,17 18,19,20,21, 22,23,24,25,26,27, 42°10,11, 12,13,14,15,16,17, 19,20,21,22,23. 18, 43° 5,6,7,8,9,10,11,12,13, 15,16,17,18,19,20, 14, 44° 1 2,3,4,5,6,7,8,9,10,12,13,14,15,16,17, 11, 45° 0,1,2,3,4,5,6, 7,8,9,10,11,12, 46° 01,2,3,4,5,6, n 1,75 41° 15,16, 17,18,19,20,21, 22,23,24,25, 42° 10,11,12,13,14,15,16, 17,18,19,20,21,22, 43° 5,6, 7,8,9,10,11,12,13,14,15,16,17,18,19, 44° 1 2,3,4,5,6,7,8,9,10, 12,13,14,15, 11, 45°0,1,2,3,4,5,6, 7,8,9,10,11,12, 44° 0,1, 2,3, n 1,80 41° 14,15,16,17,18,19, 20,21,22,23,24, 42° 10,11, 12,13,14,15,16, 17,18,19,20,21,43° 5,6, 7,8,9,10,11,12,13, 14,15,16,17,18,19, 44° 2,3,4,5,6,7,8,9,10,11,12,13,14, 45° 0,1,2,3,4,5,6, 7,8,9,10,11, 46° 0,1, 2,3, n 1,85 41°14,15, 16,17,18, 19,20,21,22,23, 42° 9,10, 11,12,13,14,15,16,17,18,19,20, 43° 5 6,7,8,9,10,11,12, 13,14,15,16,17, 44°2,3,4,5,6,7,8,9,10, 11,12,13,14, 45° 0,1,2,3,4,5,6, 7,8,9,10,11, 46° 01,2,3, n 1,90 41° 14,15, 16,17,18, 19,20,21,22, 42° 9,10, 11,12,13,14,15,16,17,18,19,20, 43° 5 6,7,8,9,10,11,12, 13,14,15,16,17, 44° 12,3,4,5,6,7,8,9, 10,11,12,13,14, 45° 0,1,2,3,4,5,6, 7,8,9, 46° 0 1,2,3,n 1,95 41° 13,14, 15,16,17, 18,19,20,21,22, 42° 9,10, 11,12,13,14,15,16,17,18,19,20, 43° 5 6,7,8,9,10,11,12, 13,14,15,16, 44° 12,3,4,5,6,7,8,9, 10,11,12,13, 45° 0,1,2,3,4,5,6, 7,8,9, 46° 0 1,2,3, n2,00 41° 13,14, 15,16,17, 18,19,20,21,22, 42° 8,9, 10,11,12,13,14,15,16,17, 43° 4,5, 6,7,8,9,10,11, 12,13,14,15,16, 44° 1 2,3,4,5,6,7,8,9,10,11,12, 45° 0,1,2,3,4,5,6, 7,8,9, 46° 0 1,2,3, n 2,05 41° 13,14,15,16,17, 18,19, 42° 8,9, 10,11,12,13,14, 15,16, 43° 4,5, 6,7,8,9,10,11,12,13,14, 44° 1 2,3,4,5,6,7,8,9, 10,11,12, 45° 0,1,2,3,4,5,6, 7,8,9, 46°0 1,2,3, n 2,10 41° 12,13, 14,15,16, 17,18,19, 42° 8,9, 10,11,12,13,14,15,16, 43° 4,5, 6,7,8,9,10,11, 12,13,14, 44° 1 2,3,4,5,6,7,8,9,10,11,12, 45° 0,1,2,3,4,5,6, 7,8, 46° 0 1,2,3, n 2,15 41° 12,13,14,15,16, 17,18, 42° 8,9, 10,11,12,13, 14,15,16, 43° 4 5,6,7,8,9,10,11,12,13,14, 44° 1 2,3,4,5,6,7,6,9, 10,11 45° 0,1,2,3,4,5,6, 7,8, 46° 01,2,3,4, n 2,20 41° 12,13, 14,15, 16,17,18, 42° 8,9, 10,11,12,13, 14,1543° 4 5,6,7,8,9,10,11, 12,13, 44° 1 2,3,4,5,6,7,8, 9,10, 45°0,1,2,3,4,5, 6,7,8 46° 0 1,2,3,4, n 2,25 41° 12,13, 14,16, 16,17, 42°8,9, 10,11,12,13, 14,15, 43° 4 5,6,7,8,9,10,11, 12,13, 44° 1 4,5,6,7,8,9,10, 45° 0,1,2,3,4,5, 6,7,8, 46° 0 1,2,3, n 2,30 41° 12,13, 14,15,16,17, 42° 7,8, 9,10,11,12,13, 14,15, 43° 4 5,6,7,8,9,10, 11,12,13, 44°1 2,3,4,5,6,7,8, 9,10, 45° 0,1,2,3,4,5, 6,7, 46° 0 1,2,3, n 2,35 41°11,12, 13,14,15, 16,17, 42° 7,8, 9,10,11,12, 13,14, 43° 4 5,6,7,8,9,10,11,12, 44° 1 2,3,4.5,6,7, 8,9,10, 45° 0,1,2,3,4,5, 6,7, 46° 0 1,2,3, n2,40 41° 11,12, 13,14, 15,16, 42° 7,8, 9,10,11,12, 13,14, 43° 45,6,7,8,9, 10,11,12, 44° 1 2,3,4,5,6,7, 8,9,10, 45° 0,1,2,3,4. 5,6,7,46° 0 1,2,3, n 2,45 41° 42° 7,8, 9,10,11, 12,13,14, 43° 4 5,6,7,8,9,10,11,12, 44° 1 2,3,4,5,6,7, 8,9,10, 45° 0,1,2,3,4, 5,6,7, 46° 0 1,2,3,n 2,50 41° 11,12, 13 14,15,16, 42° 7,8, 9,10,11, 12,13,14, 43° 45,6,7,8,9, 10,11, 44° 1 2,3,4,5,6,7, 8,9, 45° 0,1,2,3,4, 5,6,7, 46°0,1,2, n 2,55 41° 11,12, 13,14, 15,18, 42° 7,8, 9,10,11, 12,13,14, 43° 45,6,7,8,9, 10,11,12, 44° 1 2,3,4,5,6,7, 8,9,10, 45° 0,1,2,3,4, 5,6,7,46° 0 1,2,3, n 2,60 41° 11,12, 13 14,15, 42° 7,8, 9,10,11, 12,13, 43° 45,6,7,8,9, 10,11, 44° 1 2,3,4,5,6,7, 8,9, 45° 0,1,2,3, 4,5,6,7, 46°0,1,2, n 2,65 41° 10,11,12, 13,14,15, 42° 7,8, 9,10, 11,12,13, 43° 45,6,7,8,9, 10,11, 44° 1 2,3,4,5,6, 7,8,9, 45° 0,1,2,3, 4,5,6, 46° 0,1,2,n 2,70 41° 10,11,12, 13,14,15, 42° 7,8, 9,10, 11,12,13, 43° 4 5,6,7,8,9,10,11, 44° 1 2,3,4,5,6, 7,8,9, 45° 0,1,2,3, 4,5,6, 46° 0,1,2, n 2,75 41°10,11,12, 13,14,15, 42° 7,8, 9,10, 11,12, 43° 4 5,6,7,8, 9,10,11, 44° 12,3,4,5,6, 7,8,9, 45° 0,1,2,3, 4,5,6, 46° 0,1, n 2,80 41° 10,11,12,13,14,15, 42° 7,8, 9,10, 11,12, 43° 4 5,6,7,8, 9,10, 44° 1 2,3,4,5,6,7,8, 45° 0,1,2,3, 4,5,6, 46° 0,1, n 2,85 41° 10,11,12, 13,14, 42° 7,8, 910,11,12, 43° 4 5,6,7,8, 9,10, 44° 1 2,3,4,5,6, 7,8, 45° 0,1,2,3, 4,5,6,46° 0,1, n 2,90 41° 10,11,12, 13,14, 42° 7,8, 9 10,11,12, 43° 4 5,6,7,8,9,10, 44° 1 2,3,4,5,6, 7,8, 45° 0,1,2,3, 4,5,6, 46° 0,1, n 2,95 41°10,11,12, 13,14, 42° 7 8,9, 10,11,12, 43° 4 5,6,7,8, 9,10, 44° 12,3,4,5,6, 7,8, 45° 0,1,2,3, 4,5,6, 46° n 3,00 41° 10,11,12, 13,14, 42°7 8,9, 10,11,12, 43° 4 5,6,7,8, 9,10, 44° 1 2,3,4,5,6, 7,8, 45° 0,1,2,3,4,5,6, 46° 0,1,

The invention being thus described, it will be apparent that the samemay be varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be recognized by one skilled in the art areintended to be included within the scope of the following claims.

What is claimed is:
 1. A cut gem including high reflection with at leastthree principal pavilion facets and at least three principal crownfacets, an angle between the principal pavilion facets and a girdlesurface being greater than an angle between the principal crown facetsand the girdle surface, such that at angle 0° a table is formed insteadof the principal crown facets, with principal pavilion facet angle(UHFW) ranging between 41° and 46° and principal crown facet angle(ORFW) corresponding to an angle selected from a group of predetermined,preferred angles, which are subject to mean optical refraction n rangingbetween 1.50 and 3.00 of a raw material to be cut, and principalpavilion facet angle (UHFW), said group of predetermined, preferredangles comprising the following angles: at n 1.50 and UHFW of 42°anglesof 13° to 33° at n 1.50 and UHFW of 43°angles of 6° to 26° at n 1.50 andUHFW of 44°angles of 1° to 18° at n 1.50 and UHFW of 45°angles of 0° to9° at n 1.50 and UHFW of 46°angles of 0° at n 1.55 and UHFW of 41°anglesof 18° to 33° at n 1.55 and UHFW of 42°angles of 12° to 30° at n 1.55and UHFW of 43°angles of 6° to 26° at n 1.55 and UHFW of 44°angles of 1°to 18° at n 1.55 and UHFW of 45°angles of 0° to 13° at n 1.55 and UHPWof 46°angles of 0° to 5° at n 1.60 and UHFW of 41°angles of 17° to 31°at n 1.60 and UHFW of 42°angles of 11° to 28° at n 1.60 and UHEW of43°angles of 6° to 23° at n 1.60 and UHFW of 44°angles of 1° to 20° at n1.60 and UHFW of 45°angles of 0° to 14° at n 1.60 and UHFW of 46°anglesof 0° to 6° at n 1.65 and UHFW of 41°angles of 16° to 28° at n 1.65 andUHFW of 42°angles of 11° to 25° at n 1.65 and UHFW of 43°angles of 5° to21° at n 1.65 and UHFW of 44°angles of 1° to 17° at n 1.65 and UHFW of45°angles of 0° to 14° at n 1.65 and UHFW of 46°angles of 0° to 6° at n1.70 and UHFW of 41°angles of 15° to 27° at n 1.70 and UHFW of 42°anglesof 10° to 23° at n 1.70 and UHFW of 43°angles of 5° to 20° at n 1.70 andUHFW of 44°angles of 1°to 17° at n 1.70 and UHFW of 45°angles of 0° to12° at n 1.70 and UHFW of 46°angles of 0° to 6° at n 1.75 and UHFW of41°angles of 15° to 25° at n 1.75 and UHFW of 42°angles of 10° to 22° atn 1.75 and UHFW of 43°angles of 5° to 19° at n 1.75 and UHFW of44°angles of 1°to 15° at n 1.75 and UHFW of 45°angles of 0° to 12° at n1.75 and UHFW of 46°angles of 0° to 3° at n 1.80 and UHFW of 41°anglesof 14° to 24° at n 1.80 and UHFW of 42°angles of 1° to 21° at n 1.80 andUHFW of 43°angles of 5° to 19° at n 1.80 and UHFW of 44°angles of 1° to14° at n 1.80 and UHFW of 45°angles of 0° to 11° at n 1.80 and UHFW of46°angles of 0° to 3° at n 1.85 and UHFW of 41°angles of 14° to 23° at n1.85 and UHFW of 42°angles of 9° to 20° at n 1.85 and UHFW of 43°anglesof 5° to 17° at n 1.85 and UHFW of 44°angles of 1° to 14° at n 1.85 andUHFW of 45°angles of 0° to 11° at n 1.85 and UHFW of 46°angles of 0° to3° at n 1.90 and UHFW of 41°angles of 14° to 22° at n 1.90 and UHFW of42°angles of 9° to 20° at n 1.90 and UHFW of 43°angles of 5° to 17° at n1.90 and UHFW of 44°angles of 1° to 14° at n 1.90 and UHFW of 45°anglesof 0° to 9° at n 1.90 and UHFW of 46°angles of 0° to 3° at n 1.95 andUHFW of 41°angles of 13° to 22° at n 1.95 and UHFW of 42°angles of 9° to20° at n 1.95 and UHFW or 43°angles of 5° to 16° at n 1.95 and UHFW of44°angles of 1° to 13° at n 1.95 and UHFW of 45°angles of 0° to 9° at n1.95 and UHFW of 46°angles of 0° to 3° at n 2.00 and UHFW of 41°anglesof 13° to 22° at n 2.00 and UHFW of 42°angles of 8° to 17° at n 2.00 andUHFW of 43°angles of 4° to 16° at n 2.00 and UHFW of 44°angles of 1° to12° at n 2.00 and UHFW of 45°angles of 0° to 9° at n 2.00 and UHFW of46°angles of 0° to 3° at n 2.05 and UHFW of 41°angles of 13° to 19° at n2.05 and UHFW of 42°angles of 8° to 16° at n 2.05 and UHFW of 43°anglesof 4° to 14° at n 2.05 and UHFW of 44°angles of 1° to 12° at n 2.05 andUHFW of 45°angles of 0° to 9° at n 2.05 and UHFW of 46°angles of 0° to3° at n 2.10 and UHFW of 41°angles of 12° to 19° at n 2.10 and UHFW of42°angles of 8° to 16° at n 2.10 and UHFW of 43°angles of 4° to 14° at n2.10 and UHFW of 44°angles of 1° to 12° at n 2.10 and UHFW of 45°anglesof 0° to 8° at n 2.10 and UHFW of 46°angles of 0° to 3° at n 2.15 andUHFW of 41°angles of 12° to 18° at n 2.15 and UHFW of 42°angles of 8° to16° at n 2.15 and UHFW of 43°angles of 4° to 14° at n 2.15 and UHFW of44°angles of 1° to 11° at n 2.15 and UHFW of 45°angles of 0° to 8° at n2.15 and UHFW of 46°angles of 0° to 4° at n 2.20 and UHFW of 41°anglesof 12° to 18° at n 2.20 and UHFW of 42°angles of 8° to 15° at n 2.20 andUHFW of 43°angles of 4° to 13° at n 2.20 and UHFW of 44°angles of 1° to10° at n 2.20 and UHFW of 45°angles of 0° to 8° at n 2.20 and UHFW of46°angles of 0° to 4° at n 2.25 and UHFW of 41°angles of 12° to 17° at n2.25 and UHFW of 42°angles of 8° to 15° at n 2.25 and UHFW of 43°anglesof 4° to 13° at n 2.25 and UHFW of 44°angles of 1° to 10° at n 2.25 andUHFW of 45°angles of 0° to 8° at n 2.25 and UHFW of 46°angles of 0° to3° at n 2.30 and UHFW of 41°angles of 12° to 17° at n 2.30 and UHFW of42°angles of 7° to 15° at n 2.30 and UHFW of 43°angles of 4° to 13° at n2.30 and UHFW of 44°angles of 1° to 10° at n 2.30 and UHFW of 45°anglesof 0° to 7° at n 2.30 and UHFW of 46°angles of 0° to 3° at n 2.35 andUHFW of 41°angles of 11° to 17° at n 2.35 and UHFW of 42°angles of 7° to14° at n 2.35 and UHFW of 43°angles of 4° to 12° at n 2.35 and UHFW of44°angles of 1° to 10° at n 2.35 and UHFW of 45°angles of 0° to 7° at n2.35 and UHFW of 46°angles of 0° to 3° at n 2.40 and UHFW of 41°anglesof 11° to 16° at n 2.40 and UHFW of 42°angles of 7° to 14° at n 2.40 andUHFW of 43°angles of 4° to 12° at n 2.40 and UHFW of 44°angles of 1° to10° at n 2.40 and UHFW of 45°angles of 0° to 7° at n 2.40 and UHFW of46°angles of 0° to 3° at n 2.45 and UHFW of 41°angles of 11° to 16° at n2.45 and UHFW of 42°angles of 7° to 14° at n 2.45 and UHFW of 43°anglesof 4° to 12° at n 2.45 and UHFW of 44°angles of 1° to 10° at n 2.45 andUHFW of 45°angles of 0° to 7° at n 2.45 and UHFW of 46°angles of 0° to3° at n 2.50 and UHFW of 41°angles of 11° to 16° at n 2.50 and UHFW of42°angles of 7° to 14° at n 2.50 and UHFW of 43°angles of 4° to 11° at n2.50 and UHFW of 44°angles of 1° to 9° at n 2.50 and UHFW of 45°anglesof 0° to 7° at n 2.50 and UHFW of 46°angles of 0° to 3° at n 2.55 andUHFW of 41°angles of 11° to 15° at n 2.55 and UHFW of 42°angles of 7° to13° at n 2.55 and UHFW of 43°angles of 4° to 11° at n 2.55 and UHFW of44°angles of 1° to 9° at n 2.55 and UHFW of 45°angles of 0° to 7° at n2.55 and UHFW of 46°angles of 0° to 2° at n 2.60 and UHFW of 41°anglesof 11° to 15° at n 2.60 and UHFW of 42°angles of 7° to 13° at n 2.60 andUHFW of 43°angles of 4° to 11° at n 2.60 and UHFW of 44°angles of 1° to9° at n 2.60 and UHFW of 45°angles of 0° to 7° at n 2.60 and UHFW of46°angles of 0° to 2° at n 2.65 and UHFW of 41°angles of 10° to 15° at n2.65 and UHFW of 42°angles of 7° to 13° at n 2.65 and UHFW of 43°anglesof 4° to 11° at n 2.65 and UHFW of 44°angles of 1° to 9° at n 2.65 andUHFW of 45°angles of 0° to 6° at n 2.65 and UHFW of 46°angles of 0° to2° at n 2.70 and UHFW of 41°angles of 10° to 15° at n 2.70 and UHFW of42°angles of 7° to 13° at n 2.70 and UHFW of 43°angles of 4° to 11° at n2.70 and UHFW of 44°angles of 1° to 9° at n 2.70 and UHFW of 45°anglesof 0° to 6° at n 2.70 and UHFW of 46°angles of 0° to 2° at n 2.75 andUHFW of 41°angles of 10° to 15° at n 2.75 and UHFW of 42°angles of 7° to12° at n 2.75 and UHFW of 43°angles of 4° to 11° at n 2.75 and UHFW of44°angles of 1° to 9° at n 2.75 and UHFW of 45°angles of 0° to 6° at n2.75 and UHFW of 46°angles of 0° to 1° at n 2.80 and UHFW of 41°anglesof 10° to 15° at n 2.80 and UHFW of 42°angles of 7° to 12° at n 2.80 andUHFW of 43°angles of 4° to 10° at n 2.80 and UHFW of 44°angles of 1° to8° at n 2.80 and UHFW of 45°angles of 0° to 6° at n 2.80 and UHFW of46°angles of 0° to 1° at n 2.85 and UHFW of 41°angles of 10° to 14° at n2.85 and UHFW of 42°angles of 7° to 12° at n 2.85 and UHFW of 43°anglesof 4° to 10° at n 2.85 and UHFW of 44°angles of 1° to 8° at n 2.85 andUHFW of 45°angles of 0° to 6° at n 2.85 and UHFW of 46°angles of 0° to1° at n 2.90 and UHFW of 41°angles of 10° to 14° at n 2.90 and UHFW of42°angles of 7° to 12° at n 2.90 and UHFW of 43°angles of 4° to 10° at n2.90 and UHFW of 44°angles of 1° to 8° at n 2.90 and UHFW of 45°anglesof 0° to 6° at n 2.90 and UHFW of 46°angles of 0° to 1° at n 2.95 andUHFW of 41°angles of 10° to 14° at n 2.95 and UHFW of 42°angles of 7° to12° at n 2.95 and UHFW of 43°angles of 4° to 10° at n 2.95 and UHFW of44°angles of 1° to 8° at n 2.95 and UHFW of 45°angles of 0° to 6° at n2.95 and UHFW of 46°angles of 0° to 1° at n 3.00 and UHFW of 41°anglesof 10° to 14° at n 3.00 and UHFW of 42°angles of 7° to 12° at n 3.00 andUHFW of 43°angles of 4° to 10° at n 3.00 and UHFW of 44°angles of 1° to8° at n 3.00 and UHFW of 45°angles of 0° to 6° at n 3.00 and UHFW of46°angles of 0° to 1° and principal crown facet angles (OHFW) for valuesof n and principal pavilion facet angles (UHFW) not specificallyspecified above being derived by interpolation from the above specifiedvalues.
 2. The cut gem according to claim 1, wherein, in addition to anumber of principal crown facets, the gem has a table of a diameterwhich preferably amounts to 0 to 85% of a diameter of the girdlesurface.
 3. The gem cut according to claim 1, wherein for a diamond thegroup of preferred principal crown facet angles (OHFW) comprises thefollowing angles: with UHFW of 41° angles of 11° to with UHFW of 42°angles of 7° to 14° with UHFW of 43° angles of 4° to 12° with UHFW of44° angles of 1° to 10° with UHFW of 45° angles of 0° to 7° with UHFW of46° angles of 0° to 3°.
 4. The cut gem according to claim 1, whereinwithin the group of preferred angles from which the principal crownfacet angle is selected is a group of especially preferred principalcrown facet angles (OHFW) comprising the following angles: with UHFW of41° of 13° to 14° with UHFW of 42° of 9° to 12° with UHFW of 43° of 5°to 9° with UHFW of 44° of 2° to 7° with UHFW of 45° of 0° to 4° withUHFW of 46° of 0°.
 5. The cut gem according to claim 4, said gem furthercomprising dependent crown facets, wherein the principal crown facetshave an angle selected from the group of especially preferred principalcrown facet angles (OHFW) and the dependent crown facets have an angleselected from the group of preferred angles.
 6. The cut gem according toclaim 1, wherein the raw material used for cutting is either a naturalstone or synthetic material.
 7. The cut gem according to claim 1,wherein, in addition to principal pavilion facets (UHFW)and principalcrown facets (OHFW), the gem has at least one of additional dependentpavilion facets and dependent crown facets.
 8. The cut gem according toclaim 1, wherein at least one of the number of pavilion facets and thenumber of crown facets is an even number.
 9. The cut gem according toclaim 8, wherein said even number is greater than
 13. 10. The cut gemaccording to claim 1, wherein at least one of the number of pavilionfacets and the number of crown facets is an odd number and is greaterthan
 13. 11. The cut gem according to claim 1, wherein the number ofprincipal crown facets and/or principal pavilion facets may be even orodd and edges between the principal pavilion facets and the principalcrown facets are mutually offset on the girdle surface.
 12. The cut gemaccording to claim 1, wherein the girdle surface may be of any shape,and is either formed as an edge between the pavilion facets and thecrown facets, or consists of at least one rounded or flat facet of anyheight.
 13. The cut gem according to claim 1, wherein the gem is eithermanually or automatically cut.
 14. The cut gem according to claim 1,wherein at least one of the number of pavilion facets and the number ofcrown facets is an odd number.
 15. A cut gem including high reflectionwith at least three principal pavilion facets and at least threeprincipal crown facets, an angle between the principal pavilion facetsand a girdle surface being greater than an angle between the principalcrown facets and the girdle surface, such that at angle 0° a table isformed instead of the principal crown facets, with principal pavilionfacet angle (UHFW) ranging between 41° and 46° and principal crown facetangle (OHFW) corresponding to an angle selected from a group ofpredetermined, preferred angles, which are subject to mean opticalrefraction n ranging between 1.50 and 3.00 of a raw material to be cut,and principal pavilion facet angle (UHFW), said group of predetermined,preferred angles comprising the following angles: at n 1.50 and UHFW of42°angles of 16° to 25° at n 1.50 and UHFW of 43°angles of 10° to 21° atn 1.50 and UHFW of 44°angles of 3° to 16° at n 1.50 and UHFW of45°angles of 0° to 9° at n 1.55 and UHFW of 41°angles of 20° to 26° at n1.55 and UHFW of 42°angles of 15° to 23° at n 1.55 and UHFW of 43°anglesof 9° to 19° at n 1.55 and UHFW of 44°angles of 3° to 16° at n 1.55 andUHFW of 45°angles of 0° to 8° at n 1.60 and UHFW of 41°angles of 19° to25° at n 1.60 and UHFW of 42°angles of 14° to 21° at n 1.60 and UHFW of43°angles of 8° to 17° at n 1.60 and UHFW of 44°angles of 2° to 12° at n1.60 and UHFW of 45°angles of 0° to 7° at n 1.60 and UHFW of 46°anglesof 0° at n 1.65 and UHFW of 41°angles of 19° to 23° at n 1.65 and UHFWof 42°angles of 13° to 20° at n 1.65 and UHFW of 43°angles of 8° to 15°at n 1.65 and UHFW of 44°angles of 2° to 11° at n 1.65 and UHFW of45°angles of 0° to 6° at n 1.65 and UHFW of 46°angles of 0° at n 1.70and UHFW of 41°angles of 18° to 21° at n 1.70 and UHFW of 42°angles of12° to 18° at n 1.70 and UHFW of 43°angles of 7° to 14° at n 1.70 andUHFW of 44°angles of 2° to 11° at n 1.70 and UHFW of 45°angles of 0° to6° at n 1.70 and UHFW of 46°angles of 0° at n 1.75 and UHFW of 41°anglesof 17° to 21° at n 1.75 and UHFW of 42°angles of 12° to 16° at n 1.75and UHFW of 43°angles of 7° to 13° at n 1.75 and UHFW of 44°angles of 2°to 11° at n 1.75 and UHFW of 45°angles of 0° to 6° at n 1.75 and UHFW of46°angles of 0° to 1° at n 1.80 and UHFW of 41°angles of 16° to 19° at n1.80 and UHFW of 42°angles of 12° to 16° at n 1.80 and UHFW of 43°anglesof 7° to 13° at n 1.80 and UHFW of 44°angles of 2° to 10° at n 1.80 andUHFW of 45°angles of 0° to 6° at n 1.80 and UHFW of 46°angles of 0° to1° at n 1.85 and UHFW of 41°angles of 16° to 18° at n 1.85 and UHFW of42°angles of 11° to 15° at n 1.85 and UHFW of 43°angles of 6° to 12° atn 1.85 and UHFW of 44°angles of 2° to 10° at n 1.85 and UHFW of45°angles of 0° to 6° at n 1.85 and UHFW of 46°angles of 0° at n 1.90and UHFW of 41°angles of 16° to 18° at n 1.90 and UHFW of 42°angles of11° to 14° at n 1.90 and UHFW of 43°angles of 6° to 12° at n 1.90 andUHFW of 44°angles of 2° to 9° at n 1.90 and UHFW of 45°angles of 0° to6° at n 1.90 and UHFW of 46°angles of 0° at n 1.95 and UHFW of 41°anglesof 15° to 17° at n 1.95 and UHFW of 42°angles of 11° to 14° at n 1.95and UHFW of 43°angles of 6° to 12° at n 1.95 and UHFW of 44°angles of 2°to 9° at n 1.95 and UHFW of 45°angles of 0° to 6° at n 1.95 and UHFW of46°angles of 0° at n 2.00 and UHFW of 41°angles of 15° to 17° at n 2.00and UHFW of 42°angles of 10° to 14° at n 2.00 and UHFW of 43°angles of6° to 12° at n 2.00 and UHFW of 44°angles of 2° to 9° at n 2.00 and UHFWof 45°angles of 0° to 6° at n 2.00 and UHFW of 46°angles of 0° at n 2.05and UHFW of 41°angles of 15° to 17° at n 2.05 and UHFW of 42°angles of10° to 14° at n 2.05 and UHFW of 43°angles of 6° to 11° at n 2.05 andUHFW of 44°angles of 2° to 9° at n 2.05 and UHFW of 45°angles of 0° to6° at n 2.05 and UHFW of 46°angles of 0° at n 2.10 and UHFW of 41°anglesof 14° to 16° at n 2.10 and UHFW of 42°angles of 10° to 14° at n 2.10and UHFW of 43°angles of 6° to 11° at n 2.10 and UHFW of 44°angles of 2°to 9° at n 2.10 and UHFW of 45°angles of 0° to 6° at n 2.10 and UHFW of46°angles of 0° at n 2.15 and UHFW of 41°angles of 14° to 16° at n 2.15and UHFW of 42°angles of 10° to 13° at n 2.15 and UHFW of 43°angles of5° to 11° at n 2.15 and UHFW of 44°angles of 2° to 9° at n 2.15 and UHFWof 45°angles of 0° to 6° at n 2.15 and UHFW of 46°angles of 0° at n 2.20and UHFW of 41°angles of 14° to 15° at n 2.20 and UHFW of 42°angles of10° to 13° at n 2.20 and UHFW of 43°angles of 5° to 11° at n 2.20 andUHFW of 44°angles of 2° to 8° at n 2.20 and UHFW of 45°angles of 0° to5° at n 2.20 and UHFW of 46°angles of 0° at n 2.25 and UHFW of 41°anglesof 14° to 15° at n 2.25 and UHFW of 42°angles of 10° to 13° at n 2.25and UHFW of 43°angles of 5° to 11° at n 2.25 and UHFW of 44°angles of 2°to 8° at n 2.25 and UHFW of 45°angles of 0° to 5° at n 2.25 and UHFW of46°angles of 0° at n 2.30 and UHFW of 41°angles of 14° to 15° at n 2.30and UHFW of 42°angles of 9° to 13° at n 2.30 and UHFW of 43°angles of 5°to 10° at n 2.30 and UHFW of 44°angles of 2° to 8° at n 2.30 and UHFW of45°angles of 0° to 5° at n 2.30 and UHFW of 46°angles of 0° at n 2.35and UHFW of 41°angles of 13° to 15° at n 2.35 and UHFW of 42°angles of9° to 12° at n 2.35 and UHFW of 43°angles of 5° to 10° at n 2.35 andUHFW of 44°angles of 2° to 7° at n 2.35 and UHFW of 45°angles of 0° to5° at n 2.35 and UHFW of 46°angles of 0° at n 2.40 and UHFW of 41°anglesof 13° to 14° at n 2.40 and UHFW of 42°angles of 9° to 12° at n 2.40 andUHFW of 43°angles of 5° to 9° at n 2.40 and UHFW of 44°angles of 2° to7° at n 2.40 and UHFW of 45°angles of 0° to 4° at n 2.40 and UHEW of46°angles of 0° at n 2.45 and UHFW of 41°angles of 13° to 14° at n 2.45and UHFW of 42°angles of 9° to 11° at n 2.45 and UHFW of 43°angles of 5°to 9° at n 2.45 and UHFW of 44°angles of 2° to 7° at n 2.45 and UHFW of45°angles of 0° to 4° at n 2.45 and UHFW of 46°angles of 0° at n 2.50and UHFW of 41°angles of 13° at n 2.50 and UHFW of 42°angles of 9° to11° at n 2.50 and UHFW of 43°angles of 5° to 9° at n 2.50 and UHFW of44°angles of 2° to 7° at n 2.50 and UHFW of 45°angles of 0° to 4° at n2.55 and UHFW of 41°angles of 13° at n 2.55 and UHFW of 42°angles of 9°to 11° at n 2.55 and UHFW of 43°angles of 5° to 9° at n 2.55 and UHFW of44°angles of 2° to 7° at n 2.55 and UHFW of 45°angles of 0° to 3° at n2.60 and UHFW of 41°angles of 13° at n 2.60 and UHFW of 42°angles of 9°to 11° at n 2.60 and UHFW of 43°angles of 5° to 9° at n 2.60 and UHFW of44°angles of 2° to 7° at n 2.60 and UHFW of 45°angles of 0° to 3° at n2.65 and UHFW of 42°angles of 9° to 11° at n 2.65 and UHFW of 43°anglesof 5° to 9° at n 2.65 and UHFW of 44°angles of 2° to 6° at n 2.65 andUHFW of 45°angles of 0° to 3° at n 2.70 and UHFW of 42°angles of 9° to10° at n 2.70 and UHFW of 43°angles of 5° to 9° at n 2.70 and UHFW of44°angles of 2° to 6° at n 2.70 and UHFW of 45°angles of 0° to 3° at n2.75 and UHFW of 42°angles of 9° to 10° at n 2.75 and UHFW of 43°anglesof 5° to 8° at n 2.75 and UHFW of 44°angles of 2° to 6° at n 2.75 andUHFW of 45°angles of 0° to 3° at n 2.80 and UHFW of 42°angles of 9° to10° at n 2.80 and UHFW of 43°angles of 5° to 8° at n 2.80 and UHFW of44°angles of 2° to 6° at n 2.80 and UHFW of 45°angles of 0° to 3° at n2.85 and UHFW of 42°angles of 9° at n 2.85 and UHFW of 43°angles of 5°to 8° at n 2.85 and UHFW of 44°angles of 2° to 6° at n 2.85 and UHFW of45°angles of 0° to 3° at n 2.90 and UHFW of 42°angles of 9° at n 2.90and UHFW of 43°angles of 5° to 8° at n 2.90 and UHFW of 44°angles of 2°to 6° at n 2.90 and UHFW of 45°angles of 0° to 3° at n 2.95 and UHFW of42°angles of 8° to 9° at n 2.95 and UHFW of 43°angles of 5° to 8° at n2.95 and UHFW of 44°angles of 2° to 6° at n 2.95 and UHFW of 45°anglesof 0° to 3° at n 3.00 and UHEW of 42°angles of 8° to 9° at n 3.00 andUHFW of 43°angles of 5° to 8° at n 3.00 and UHFW of 44°angles of 2° to6° at n 3.00 and UHFW of 45°angles of 0° to 3° and principal crown facetangles (OHFW) for values of n and principal pavilion facet angles (UHFW)not specifically specified above being derived by interpolation from theabove specified values.
 16. The cut gem according to claim 15, wherein,in addition to a number of principal crown facets, the gem has a tableof a diameter which preferably amounts to 0 to 85% of a diameter of thegirdle surface.
 17. The cut gem according to claim 15, wherein for adiamond the group of preferred principal crown facet angles (OHFW)comprises the following angles: with UHFW of 41°angles of 11° to withUHFW of 42°angles of 7° to 14° with UHFW of 43°angles of 4° to 12° withUHFW of 44°angles of 1° to 10° with UHFW of 45°angles of 0° to 7° withUHFW of 46°angles of 0° to 3°.
 18. The cut gem according to claim 15,wherein within the group of preferred angles from which the principalcrown facet angle is selected is a group of especially preferredprincipal crown facet angles (OHFW) comprising the following angles:with UHFW of 41°angles of 13° to 14° with UHFW of 42°angles of 9 to 12°with UHFW of 43°angles of 5° to 9° with UHFW of 44°angles of 2° to 7°with UHFW of 45°angles of 0° to 4° with UHFW of 46°angles of 0°.
 19. Thecut gem according to claim 18, said gem further comprising dependentcrown facets, wherein the principal crown facets have an angle selectedfrom the group of especially preferred principal crown facet angles(OHFW) and the dependent crown facets have an angle selected from thegroup of preferred angles.
 20. The cut gem according to claim 15,wherein the raw material used for cutting is either a natural stone orsynthetic material.
 21. The cut gem according to claim 15, wherein, inaddition to principal pavilion facets (UHFW)and principal crown facets(OHFW), the gem has at least one of additional dependent pavilion facetsand dependent crown facets.
 22. The cut gem according to claim 15,wherein at least one of the number of pavilion facets and the number ofcrown facets is an even number.
 23. The cut gem according to claim 22,wherein said even number is greater than
 13. 24. The cut gem accordingto claim 15, wherein at least one of the number of pavilion facets andthe number of crown facets is an odd number.
 25. The cut gem accordingto claim 24, wherein said odd number is greater than
 13. 26. The cut gemaccording to claim 15, wherein the number of principal crown facetsand/or principal pavilion facets may be even or odd and edges betweenthe principal pavilion facets and the principal crown facets aremutually offset on the girdle surface.
 27. The cut gem according toclaim 15, wherein the girdle surface may be of any shape, and is eitherformed as an edge between the pavilion facets and the crown facets, orconsists of at least one rounded or flat facet of any height.
 28. Thecut gem according to claim 15, wherein the gem is either manually orautomatically cut.